alessandrolomanto / k8s-containerd-containerday2021

Prerequisites

To follow Vagrant tutorial, you need:

• VirtualBox - Follow installation guide on https://www.virtualbox.org/wiki/Downloads to install VirtualBox
• Vagrant - Follow installation guide on https://www.vagrantup.com/docs/installation/index.html to install Vagrant

Step 1 - Start Kubernetes Vagrant cluster

make vagrant-start

Step 2 - Try Kubernetes Cluster

vagrant ssh master

kubectl get all --all-namespaces

Step Destroy - Delete Kubernetes Cluster and Machine

make vagrant-destroy

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View kubelet log for dockershim deprecation

• Open var/log/syslog

cat var/log/syslog | grep dockershim 

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Configure containerd as container runtime

Drain node because of scheduler

kubectl drain node-2 --ignore-daemonsets

SSH to node

• Password kubeadmin

ssh root@node-2

Stop kubelet and docker services

systemctl stop kubelet
systemctl stop docker

Remove Docker software

apt remove --purge docker-ce docker-ce-cli

Make sure that containerd configuration allows disabled_plugin

• Comment #disabled_plugins=["cri"]

vi /etc/containerd/config.toml 

Restart containerd

systemctl restart containerd

Change kubelet configuration

• Add --container-runtime=remote --container-runtime-endpoint=unix:///run/containerd/containerd.sock

vi /var/lib/kubelet/kubeadm-flags.env

Start kubelet and return controlplane

systemctl start kubelet
exit

Make node-2 avaible and try new deployment

kubectl uncordon node-2
kubectl create deploy nginx --image=nginx --replicas=4

• kubectl get pods -o wide - To see that the pods are running in both nodes